Orofacial Development Flashcards
When does the development of orofacial structures occur during prenatal development?
The development of orofacial structures occurs from the fourth week to the twelfth week of prenatal development, spanning the later part of the embryonic period and the early part of the fetal period.
Which structures are involved in the development of the orofacial region?
The orofacial structures that develop during this time include the palate, nasal septum, nasal cavity, and tongue.
When does the formation of the palate occur during prenatal development?
The formation of the palate begins in the embryo and continues into the fetus, taking place over several weeks of prenatal development.
When does the formation of the palate begin during prenatal development?
The formation of the palate begins during the fifth week of prenatal development within the embryonic period.
What are the two embryonic structures involved in the formation of the palate?
The two embryonic structures involved in the formation of the palate are the primary palate and the secondary palate.
When is the palate completed during prenatal development?
The palate is completed during the twelfth week within the fetal period.
How is the final palate developed during prenatal development?
The final palate is developed in three consecutive stages: 1. Formation of the primary palate 2. Formation of the secondary palate 3. Completion of the final palate
How is the final palate completed during prenatal development?
The completion of the final palate involves the fusion of swellings or tissue from different surfaces of the embryo to meet and join.
When does the intermaxillary segment form during prenatal development?
The intermaxillary segment forms during the fifth week of prenatal development.
How does the intermaxillary segment form?
The intermaxillary segment forms as a result of the fusion of the two medial nasal processes internally within the embryo.
What does the intermaxillary segment give rise to during prenatal development?
The intermaxillary segment gives rise to the primary palate (or primitive palate).
What role does the primary palate serve during its formation?
At the time of its formation, the primary palate serves as a partial separation between the developing oral cavity proper and the nasal cavity.
What will the primary palate form in future development?
In future development, the primary palate will form the premaxillary part of the maxilla, which is the anterior one-third of the hard palate.
Where is the premaxillary part of the hard palate located, and what does it contain?
The premaxillary part of the hard palate is located anterior to the incisive foramen and contains the maxillary incisors.
During the sixth week of prenatal development, the bilateral maxillary processes will give rise to two ___?
During the sixth week of prenatal development, the bilateral maxillary processes give rise to two palatal shelves (or lateral palatine processes).
When and where is the tongue forming during prenatal development?
The tongue is forming on the floor of the primitive pharynx during the sixth week of development, at the same time the bilateral maxillary processes give rise to two palatal shelves.
What happens intially as the tongue grows during prenatal development?
As the tongue grows, it initially fills the common nasal and oral cavity.
How does the developing tongue assist in the fusion of the palatal shelves?
As the developing tongue muscles begin to function, the tongue contracts and moves out of the way of the developing lateral palatal shelves, helping avoid any obstacle to their future fusion by moving both anteriorly and inferiorly.
What does the secondary palate give rise to during prenatal development?
The secondary palate gives rise to the posterior two-thirds of the hard palate, which contains certain maxillary anterior teeth (canines) and posterior teeth, all located posterior to the incisive foramen.
What else does the secondary palate give rise to during prenatal development?
The secondary palate also gives rise to the soft palate and its uvula.
What do the median palatine raphe and median palatine suture indicate?
The median palatine raphe within the mucosa lining and the associated deeper median palatine suture on the adult maxillary bone indicate the line of fusion of the palatal shelves.
How is the palate completed during prenatal development?
The palate is completed when the posterior part of the primary palate meets the secondary palate due to increased growth, and they gradually fuse in an anterior to posterior direction.
What happens when all three palatal processes completely fuse?
When all three palatal processes completely fuse, they form the final palate.
What does the final palate include?
The final palate includes both the hard and soft palate.
When does the fusion of the palatal processes into the final palate occur?
The fusion of the palatal processes into the final palate occurs during the twelfth week of prenatal development.
What happens when the palatal processes fuse during the twelfth week of prenatal development?
When the palatal processes fuse, the mature oral cavity becomes completely separated from the nasal cavity, which has begun developing its nasal septum.
What causes a cleft palate?
A cleft palate is caused by the failure of fusion of the palatal shelves with the primary palate and/or with each other.
What are the potential outcomes of a cleft palate?
A cleft palate can result in varying degrees of disability.
What factors may contribute to the development of a cleft palate?
A cleft palate may be hereditary or associated with environmental factors.
How common is cleft palate?
Cleft palate occurs in 1 or 2 in 1000 cases, which is about 1%.
Can cleft palate occur with other abnormalities?
Yes, cleft palate may be isolated or associated with other abnormalities, such as cleft lip. It may involve only the soft palate or extend through to the hard palate.
How do isolated forms of cleft palate compare to cleft lip in terms of frequency?
Isolated forms of cleft palate are less common than cleft lip but are more common in women.
What complications can arise from a cleft palate?
Complications from a cleft palate can include difficulty with nursing or feeding, increased oronasal infections, and challenges with speech development and appearance.
What treatment options are available for cleft palate?
Treatment for cleft palate includes oral and plastic surgery with dental intervention. Additionally, speech and hearing therapy may also be necessary.
What is cleft uvula, and how is it classified in terms of cleft palate?
Cleft uvula is the least complicated form of cleft palate. It is also referred to as bifid uvula or split uvula.
How common is cleft uvula in newborns with cleft palate?
Most newborns with cleft palate also have a split uvula.
What causes a bifid uvula?
A bifid uvula results from the failure of complete fusion of the medial nasal process and maxillary processes during prenatal development.
How does the muscle composition of a bifid uvula differ from a normal uvula?
Bifid uvulas have less muscle in them than a normal uvula.
What complications can arise from a bifid uvula?
Bifid uvulas can cause recurring problems with middle ear infections.
How does the soft palate function during swallowing, and what happens if it cannot touch the back of the throat?
The soft palate is pushed backward during swallowing, preventing food and drink from entering the nasal cavity. If the soft palate cannot touch the back of the throat, food and drink may enter the nasal cavity.
How common is splitting of the uvula in newborns?
Splitting of the uvula occurs infrequently but is the most common form of oral cavity and nose area cleavage among newborns, with roughly 2% of infants having a bifid or split uvula.
What is velopharyngeal insufficiency (VPI), and how is it related to bifid uvula?
A bifid uvula may cause velopharyngeal insufficiency (VPI), a disorder where the soft palate (velum) cannot close against the posterior pharyngeal wall during speech, which is necessary to close off the nasal cavity for producing most speech sounds.
What are Epstein pearls, and do they require treatment?
Epstein pearls are small white papules seen in the palate of infants, representing trapped epithelial tissue during palatal fusion. They are a common and benign finding and usually go away on their own within a few months, requiring no treatment.
How can Epstein pearls be detected?
Epstein pearls can be noted during palpation when the infant is sucking on a clinician’s finger.
How can the presence of Epstein pearls be managed?
Epstein pearls don’t require treatment and usually resolve on their own within a few months. Friction from breastfeeding, bottle feeding, or using a pacifier or teether can help speed up the process.
When does the nasal cavity form during prenatal development?
The nasal cavity forms between the fifth and twelfth weeks of prenatal development and will later serve as part of the respiratory system.
What is happening with the nasal septum during the formation of the palate?
The future nasal septum is also developing at the same time the palate is forming, from the fused medial nasal processes.
How does the nasal septum form?
The nasal septum develops as a growth from the fused medial nasal processes and grows inferiorly and deep to these processes and superior to the stomodeum.
When does the nasal septum fuse with the final palate?
The vertical nasal septum fuses with the horizontally oriented final palate after it has formed, beginning in the ninth week and completing by the twelfth week of prenatal development.
What happens when the nasal septum and final palate fuse?
With the formation of the nasal septum and final palate, the paired nasal cavities and the single oral cavity in the fetus become completely separated.
What is a deviated septum?
A deviated septum occurs when the thin wall of the nasal septum is displaced to one side, causing an uneven separation between the left and right nasal cavities.
How is the nasal septum positioned in an ideal situation?
Ideally, the nasal septum is situated in the center of the nose, equally separating the right and left nasal cavities.
How common is a deviated septum, and what causes it?
In about 80% of people, the nasal septum is displaced from its usual midline position, making one nasal passage smaller. It may be caused by injury or occur naturally.
What are the symptoms of a deviated septum?
A deviated septum can block one side of the nose, leading to difficulty breathing, nasal congestion, nosebleeds, and frequent sinus infections.
What risk factors are associated with a deviated septum?
Risk factors for a deviated septum include playing contact sports and not wearing a seatbelt while riding in a motorized vehicle.
How is a deviated septum treated?
Treatment for a deviated septum may include medications to manage symptoms. If complications arise, surgery (septoplasty) may be required.
What is septoplasty, and when is it necessary?
Septoplasty is a surgical procedure to correct a crooked or dislocated septum, often performed as part of a nose surgery (rhinoplasty), especially when the deviated septum causes breathing difficulties or other complications.
What complications can a deviated septum cause?
A deviated septum can be associated with chronic sinus infections, postnasal drip, nasal congestion, nosebleeds, facial pain, and headaches.
When does tongue development occur during prenatal development?
The tongue develops between the fourth and eighth weeks of prenatal development.
From where does the tongue develop?
The tongue develops from independent swellings located on the floor of the primitive pharynx, formed by the first four pharyngeal arches.
How is the body of the tongue formed?
The body of the tongue develops from the first pharyngeal (branchial) arch.
How does the base of the tongue develop?
The base of the tongue develops later from the second, third, and fourth pharyngeal arches.
What is happening with the nasal septum during the formation of the palate?
The future nasal septum is developing at the same time the palate is forming, from the fused medial nasal processes.
What is the first structure that forms during tongue development?
The tongue development begins with the formation of a triangular median swelling called the tuberculum impar (or median tongue bud) during the fourth week of prenatal development.
Where is the tuberculum impar located in the developing embryo?
The tuberculum impar is located in the midline of the mandibular arch, considered the first branchial arch, at the floor of the primitive pharynx.
How do the lateral lingual swellings contribute to the tongue’s formation?
The two lateral lingual swellings (distal tongue buds) develop on each side of the tuberculum impar, grow in size, and merge to overgrow the tuberculum impar, forming the anterior two-thirds of the mature tongue.
What marks the fusion of the lateral lingual swellings?
The median lingual sulcus is a superficial demarcation marking the line of fusion of the two lateral lingual swellings.
What is the copula in tongue development?
The copula is a pair of swellings that form posterior to the fused anterior swellings of the tongue and gradually overgrow the hyoid arch to form the posterior one-third of the mature tongue.
What marks the development of the most posterior region of the tongue?
The epiglottic swelling marks the development of the most posterior region of the tongue and the site of the future epiglottis.
How is the epiglottic swelling formed?
The epiglottic swelling develops from the mesenchyme of the posterior parts of the fourth branchial arches.
When do the copula and the anterior swellings of the tongue merge?
The copula merges with the anterior swellings of the first arch during the eighth week of prenatal development.
What is the sulcus terminalis, and what does it signify in tongue development?
The sulcus terminalis is an inverted V-shaped groove marking the border between the base and body of the tongue. It also demarcates the fusion of the copula with the anterior swellings.
What is the foramen cecum, and where is it located?
The foramen cecum is a small pit-like depression at the back of the sulcus terminalis, marking the origin of the thyroglossal duct.
What role does the thyroglossal duct play in development?
The thyroglossal duct marks the origin of the thyroid gland and its migration path from the initial development site to its final location in the neck.
What happens to the thyroglossal duct before birth?
The thyroglossal duct closes off and becomes obliterated before birth, unless it undergoes cystic transformation.
What is ankyloglossia, and how does it affect the tongue?
Ankyloglossia, also known as ‘tongue-tie,’ occurs when a short lingual frenum restricts the movement of the tongue, affecting feeding and speech.
How does the lingual frenum develop before birth?
Before birth, the lingual frenum is a strong cord of tissue positioned in the center of the mouth, guiding the development of oral structures.
What are the symptoms of ankyloglossia?
Symptoms of ankyloglossia include difficulty sticking the tongue forward, trouble feeding, excessive attachment of the tongue to the bottom of the mouth, and a V-shaped notch at the tip of the tongue.
How does ankyloglossia impact tongue movement?
Ankyloglossia restricts the movement of the tongue to varying degrees and may be associated with other craniofacial abnormalities.
How is ankyloglossia treated?
Ankyloglossia can be treated with orofacial myofunctional therapy (OMT) or, if necessary, a frenectomy (surgical cutting of the lingual frenum).
Why should nursing mothers consider evaluating for ankyloglossia?
Nursing mothers who experience pain or whose baby has trouble latching on should have their child evaluated for ankyloglossia, as it can affect breastfeeding.
How can ankyloglossia impact feeding and breastfeeding?
Ankyloglossia can lead to feeding difficulties, which may affect the child’s weight gain and cause many mothers to abandon breastfeeding.
Why is the tongue important for speech and swallowing?
The tongue is one of the most important muscles for speech and swallowing, and issues like ankyloglossia can lead to eating or speech problems.
